Hot-air device



Aug. 23,1927.' 1,639,891

w. Lf. RATHJEN ET AL HOT AIRA DEVICE Original Filed Aug.l4. 1924 1N VENT'oR.

y and asa Patented` Aug. 23, 1927. UNITE-D STATES 1,639,897 PATENTOFFICE.

WILLIAM L. RATHJ'EN AND LILI-IAN K. BATHJ'EN", 0F OAKLAND, CALIFORNIA.

HOT-AIR DEVICE.

Application led August 11, 1924, Serial No. 731,994.' RenewedvJ'anuary'l, 1997.

Our invention relates to hot-air devices, land more particularly tohot-air hair dryers of a portable nature and 'for home use primarily.

The present dryersfor washed and wet hair that'we are familiar with, aremotordriven electric ones and consequently expensive and in fact toocostly for the average home, so our chiefobject is the production of asimple, durable and efficient hair dryer of a mechanical nature and onethat can be sold at a comparatively low price.

Another object is to make it of sheet metal portable unit and withoutany moving parts.

Another object is to make the dryer serf'l viceable for use on a gasplate, coal stove, electric stove, or other heat-emanating apparatus.

A further object is to aliX a hair guard to the device for marcellingthe hair and also to prevent long hair from coming into too closeproximity to the heating element.

We attain the abqve objects by the novel construction of our device, andother objects and advantages of the invention willappear inthe subjoineddescription of the accompanying sheet of drawings, in which:

Figure 1 is a plan of the invention, and Fig. 2 a vertical longitudinalsection through the same; and Fig. 3 is a front elevation of it with thehair guard removed and showing to advantage the hot-air outlet of thedevice.

Adverting to the drawings we will now describe the same in detail: Thenumeral 4 indicates the shell of the invention and it is preferablyformed of sheet-metal material. The shell has a fullopen bottom 5` whichis the inlet for the air, and has an opening 6 at its top which `is theoutlet for the heated air, and the said outlet is of small area comparedto that of the inlet. By preference, the outlet 6 is of .slot-likeformation and is exposed transversely. l

The shell is constructed so that the outlet overhangs the inlet as shownat 7 the over- .hang serving as an intermediate guard to prevent onegetting too close to the burner element. i The dot-and-dash line 8represents the surface of a gas plate, .coal stove, lelectricstove, orother heat-radiating'surface, and upon which the hot-air device isplaced; in

v the case of a gas plate, the device is set directly over the gasburner.

Within theA shell are walls 9, 10 and .11,

of the outlet as at 17 when the device is placed over a fiat heat'- ingsurface, such as a coal stove for example, the inlet opening 5 willvstill be common to,l the said chambers A, B, and C. In the last-namedapplication, additional air inlets must be provided, and we choose to.have thel inlets in both sides of the shell and at or near the base,such as slmwn at 13, Fig. 2, and we may have any number of them.

Above the said chambers, we employ an additional chamber D, havinalseparate and distinct opening 14 for the 1nlet of cold .air takenabove the heating surface 8. The outet 1'5A of this'chamber Joins thecommon. out- All the transverse walls converge toward ythe common outlet6, and the uppermost wall 16 of the' shell terminates substantially in ahorizontaLplane and-lies overl the mouth l and for a-purpose to be`resently given. f

urmounted on the top ofthe lip isa handle 18 for portable purposes, anda guard v19 for spacing the long hair 20 a safe distance from the sourceof heat. The guard is preferably formed of spring wire, and itsterminals are bent to form pivot points 21 and shouldersl 22 nearthereto. The points enter perforations 23 in each side of the shell, andthe shoulders 22 rest on the top of the lip 17. The spacing end of theguardmay be comparatively wide and have pronglike points or limits 24,and intermediate the said points the wire may be formed wavelike asshown at 25, the reason being presently set forth.

-When it is desired to remove or swing back thel hair guard fromservice, simply` spring out the points 21 from the shell,for swing theguard back on the said plvot points to the limiting rest position shownin portion at 26, Fig. 2.

In operation, the device is set over the 11o -heatin element, Immediatelthe big vol- `ume o heated air, represente by the wavy arrows, rises andis deflected by the transverse walls to the narrow and restricted outlet6. Here the said volume of heated air, together with the layer of,comparatively cold air, represented by the unwaved arrows, suckedthrough chamber D, pass through the common outlet rapidly and under avery perceptible pressure by reason of the .restricted outlet, and isdeflected horizontally by the lip 17.- The issuing hot air then spreadsfan-like and is held lfrom rising too abruptly by the blanket, so 'to'speak, of the said top layer of cooler and heavier air passingthroughlthe chamber D.

Wet hair is dried by the hot-air blast in a very few minutes, and whenthe wet hair is in the guard and contacting the Wave-like front, theresultant dried hair has the appearance of being mar-celled at suchcontacted areas, the' user of the device contact- -ing the variousportions of her hair on the wave-like front 25 during the drying period.

From the foregoing description taken in connection"with the accompanyingdrawings, the advantages of the construction and method of operationwill be readily understood by those skilled in the art to which theinvention appertains, and while we have described the principle ofoperation, to-f gether with the device which we n-oW consider to be thebestA embodiment thereof, we desire to have it understood that thedevice vshown is merely illustrative and that such changes may be made,when desired, as fall.

v ters Patent of the United States, is the folbeing lowing:

1. hot-air device of the class described, comprising a shell having twoopenings, one

being the inlet and of large area and the other the outlet and of smallareacompared to that of the inlet, and said outlet adapted for theissuance of the hot air at a pressure and velocity greater than that ofthe inlet air, and the said shell having a wall therein for additionalheating` surface and for directing the heat waves to the said outlet.

2. A. hot-air device of the class described, comprising a shell havingtwo openings, one the inlet and of large area and the other the` outletand of small area compared 3. A hot-air device of the class described,

comprising a shell having two openings, one

being the inlet and of large area and the' other the outlet and of smallarea compared to that of the inlet, and said outlet adapted for theissuance of the hot air at a pressure and velocity greater than that ofthe inlet air, and the said shell converging from the inlet opening tothe outlet opening, the latter opening overhanging the inlet opening toprevent too close proximity to the heating element.

4. A hot-air device, comprising a shell having a plurality of spacedwalls therein forming a plurality of heating chambers lil) having acommon inlet opening and con?A verging toward a common outletopening,

and` said chambers having thereabove an additional chamber with aseparate inlet opening for cold air and terminatingk in the said commonoutlet opening.

5. A hot-air device, comprising a shell having a plurality of spacedwalls therein forming a plurality of heating chambers having a commoninlet opening and converging toward a common outlet opening, and saidchambers having thereabove an additional chamber with a separate' inletOpening for cold air and terminating in the said common outlet opening,and a hair guard mounted above said outlet opening and extendingoutwardly therefrom.

6. In a hair-drying device of the class described, ahair guard adaptedtoextend therefrom 'and having its outermost edge formed prong-like andbetween said prongs having the edge formed wave-like to marcel the wethair in contact therewith in the drying of the ha-ir. 1

In testimony whereof we -aixour sig- WILLIAM' L. RATHJEN. LILLIAN K.RATHJEN.

natures.

